Our Weekly Checkup takes the temperature of the medical device industry’s three largest U.S. clusters: Massachusetts, California and Minnesota.

The MassDevice Indices are weighted according to market capitalization, based on the number of shares outstanding for each company from its most recent quarterly report and each Friday’s closing share price.

The Massachusetts index for the week ended Dec. 11 closed at 5.38, down 1.3 percent compared with the prior week. Since Jan. 1, when we began tracking these companies, the index has risen 21.4 percent.

The Minnesota index for the week ended Dec. 11 closed at 3.78, up 2.2 percent compared with the prior week. Since Jan. 1, when we began tracking these companies, the index has risen 28.3 percent.

The California index for the week ended Dec. 11 closed at 7.95, up three-quarters of 1 percent compared with the prior week. Since Jan. 1, when we began tracking these companies, the index has risen 87.2 percent.

We also create a composite index of the three regional indices and compare it with four other indices (the S&P 500, the Dow Jones Industrial Average, the Dow’s IHI medical devices index and the NASDAQ exchange):

The Weekly Checkup also compares Monday morning’s opening share prices with their value when the markets close Friday afternoon to calculate the biggest gainers and losers.

Here are the 20 firms that posted the biggest share price gains and losses during the week ended Dec. 11:

The 10 biggest gainers:

1. Viking Medical Systems Inc.: 215.79% (open $0.19; close $0.60)
2. Imaging3 Inc.: 84.81% (open $0.79; close $1.46)
3. Cerus Corp.: 40.21% (open $1.94; close $2.72)
4. Cambridge Heart Inc.: 27.14% (open $0.07; close $0.09)
5. Interleukin Genetics Inc.: 18.84% (open $0.69; close $0.82)
6. Caliper Life Sciences: 17.21% (open $2.15; close $2.52)
7. Brooks Automation Inc.: 14.10% (open $6.88; close $7.85)
8. Zoll Medical Corp.: 13.68% (open $19.89; close $22.61)
9. LeMaitre Vascular Inc.: 13.38% (open $4.41; close $5.00)
10. WuXi PharmaTech: 13.33% (open $13.88; close $15.73)

Sources: Google Finance and Yahoo! Finance.

And the 10 biggest losers:

1. Argonaut Technologies Inc.: -92.50% (open $0.20; close $0.02)
2. Cynosure Inc.: -74.08% (open $10.38; close $2.69)
3. Charles River Laboratories International Inc.: -70.28% (open $34.39; close $10.22)
4. Hypertension Diagnostics Inc.: -25.00% (open $0.10; close $0.08)
5. Oculus Innovative Sciences Inc. (Micromed): -14.29% (open $1.89; close $1.62)
6. Cardiogenesis Corp.: -13.64% (open $0.22; close $0.19)
7. icad Inc.: -12.64% (open $1.74; close $1.52)
8. Endologix Inc.: -12.58% (open $4.77; close $4.17)
9. Candela Corp.: -9.58% (open $3.34; close $3.02)
10. Clarient Inc.: -8.91% (open $2.58; close $2.35)

Sources: Google Finance and Yahoo! Finance.

Disclaimer: MassDevice.com’s rankings do not reflect an opinion of companies’ health, prospects or viability. They are intended to provide a snapshot of publicly traded medical device companies and in no way constitute a recommendation to buy or sell any particular security, portfolio of securities, transaction or investment strategy.